Hi,
Link the exact sets you're specifically looking at, if you want to compare them. There are lots of I.D. (internet direct) companies these days that have excellent options for good prices so there's tons of names out there that none of us know all of. Good marketing and in-store sales can make a brand better known of course, but that doesn't mean that they're good and usually not well priced for their actual quality. Polk has some good stuff and some rather low end stuff. Klipsch too has good stuff and run of the mill low end stuff. They'll get loud. But quality is the compromise. The SVS sets are over-priced in my opinion, but they're not bad, but they're not exceptional either. I think you can get more for your money from HTD, Chane and Ascend.
If you can spread out your spending that would be ideal. Get the ideal AVR now for your needs. Get the front stage speakers for this setup first and leave it there. Then, add the surrounds later. Add a quality sub, when you can. A quality sub would be something in the $500-ish range most likely. Lots of compromise under that price point. I realize this raises your budget. But spread it out, make it worth it, it hurts once, and sounds great the rest of the time.
Very best,